Insulated rail fastener



A 9 A. LWQNES Em 3 INSULATED RAIL FASTENER 2 Sheets-Shet 1 Filed Nov. 15, 1967 Aug. 26, 1969 A. l. w. JONES' ETAL INSULATED RAIL FASTENER F iled Nov. 15. 1967 2 Sheets-Sheet v VII United States Patent US. Cl. 238-338 6 Claims ABSTRACT OF THE DISCLOSURE A device for electrically insulating a railway rail from parts for securing it consists of an elongate metal member of substantially L-shaped cross-section and an electrically insulating member snap-fitted on the metal member and extending across those faces of the limbs of the L which are on the inside of the angle of the L and around the tip of each limb. Projections on one of the two members prevent the device from sliding along the rail. The device is placed on the edge of the rail flange with one limb of the L between a resilient rail-fastening member and the top of the flange and the other limb of the L between the edge of the rail flange and an anchoring member. The rail-fastening mmeber engages said metal member and the insulating member insulates the flange from the rail-fastening member and from the anchoring member.

This invention relates to a device for electrically insulating a railway rail from parts for securing it and to a railway rail and fastening assembly including the device.

There has previously been proposed a device for electrically insulating a flange-footed railway rail from a resilient rail-fastening member, a first part of which bears downwardly upon the top of the rail flange, and from an anchoring member, which is beside the flange and in which a second part of the rail-fastening member is inserted, said device being elongate and of substantially L-shaped cross-section, each leg of the L comprising electrically insulating material, one leg of the L being for interposition between the top of the rail flange and said first part and the other leg of the L being for interposition between the edge of the rail flange and said anchoring member, said other leg having two projections extending from it so that when said device is in use these projections can lie close to and on opposite sides of the anchoring member and can by abutting the anchoring member resist any tendency for said device to move in a direction parallel to the length of the rail.

According to a first aspect of the present invention, there is provided a device as defined above which is characterised in that it consists of an elongate metal member of substantially L-shaped cross-section and an elongate member of electrically insulating material which is a snap fit on the metal member and extends around the tip of one limb of the metal member, which is in said one leg of said device, across that face of said one limb which is on the inside of the angle of the 1, across that face of the other limb of the metal member which is on the inside of the angle of the L and then around the tip of that limb, the arrangement being such that in use of the device the said first part of the rail-fastening member directly engages said metal member and the rail is electrically insulated by the insulating member from the rail-fastening member and from said anchoring member.

There has also previously been proposed a rail-andfastening combination comprising an electrically conductive railway sleeper, a flange-footed rail resting crosswise on the sleeper, electrically insulating material between the sleeper and the foot of the rail, an anchoring member which is beside the rail flange and is fixed to the sleeper, a rail-fastening member having a first part directly above the rail flange and also having a second part inserted in said anchoring member, and a device for providing electrical insulation which is elongate and of substantially L-shaped cross-section, each leg of the L comprising electrically insulating material, one leg of the L being interposed between the top of the rail flange and said first part and the other leg of the L being interposed between the edge of the rail flange and said anchoring member, said other leg having two projections extending from it close to and on opposite sides of the anchoring member which can by abutting the anchoring member resist any tendency for said device to move in a direction parallel to the length of the rail.

According to a second aspect of the present invention, there is provided a rail-and-fastening combination as defined above which is characterised in that said device for providing electrical insulation is a device according to the first aspect of the present invention.

The aforementioned projections could be integral with the electrically insulating material of said other leg but it is preferred to have them formed on the metal member at opposite ends of it and to have the member of insulating material extending between the projections across that face of said other limb which is on the outside of the angle of the L. If the insulating material comes sufliciently close to the projections on the last-mentioned face, this can prevent the insulating member from sliding any substantial distance along the metal member.

The device according to the first aspect of the invention is an improvement upon the insulating device according to the above-mentioned prior proposal, which is made wholly of electrically insulating material, for example nylon, because the first part of the rail-fastening member does not sink into the part of the device according to the invention which it engages, i.e., the upper surface of the metal member, as it does into the electrically insulating material of the device according to the prior proposal. Therefore, there is eliminated a fault of the device according to the prior proposal, namely that, due to the sinking in, the downward pressure exerted on the rail by the rail-fastening member slowly decreases. Also, by having the first part of the rail-fastening member bear on metal instead of on insulating material, wear due to abrasion is reduced. Furthermore, to cater for variations in the distance between the edge of the rail flange and the anchoring member, for example due to gauge width variations at curves in the track, there may be manufactured several diflerent sizes of the metal member, having different thicknesses in said other leg, with only one size of the insulating member to fit on them all, this being cheaper than manufacturing several different sizes of insulating member, as would be necessary if the insulating members of the prior proposal were to be used alone. Because the insulating member is a snap fit on the metal member, no adhesive or other fixing means is necessary to hold the two parts together. They can be fitted together in a factory and delivered to the site as a unit.

An example in accordance with the present invention is described below with reference to the accompanying drawing, in which:

FIGURE 1 shows a side view of a rail-and-fastening combination according to a prior proposal,

FIGURE 2 shows a plan view of a metal member forming part of a device according to the invention,

FIGURE 3 shows an end view of the metal member,

FIGURE 4 shows a plan view of an electrically insulating member forming another part of the device, and

FIGURE 5 shows a cross-sectional view of the assembled device taken as indicated by the lines and arrows marked V-V in FIGURES 2 and 4.

FIGURE 1 shows a concrete railway sleeper 21 and a flange-footed railway rail resting crosswise on the sleeper, the flange being referenced 25. Between the foot of the rail and the sleeper there is a rubber pad 24. There are two anchoring members 22 (only one of which is shown) spaced apart along, and fixed to, the sleeper, each having a portion (not shown) extending into the concrete and each being beside one edge of the rail flange. An insulating device 26 consisting of a single moulding of nylon is placed on each edge of the rail flange, each such device being elongate and of substantially L-shaped cross-section having one leg 26A of the L lying on top of the rail flange and the other leg 26B of the L interposed between an edge of the rail flange and one of the anchoring members 22. From the leg 26B of each device 26 there extend two projections 26C which are close to and on opposite sides of the adjacent anchoring member and serve the purpose indicated above. There are two rail-fastening members (parts of one of which are represented by dotted circles) as disclosed in United States patent specification No. 3,004,716, each having a first part 29 engaging the leg 26A of one of the devices 26, and thus bearing downwardly on the rail flange, and having a second part 27 inserted in one of the anchoring members 22 and also having a third part 28 bearing downwardly upon the same anchoring member.

Two devices according to FIGURES 2 to 5 can be used instead of the devices 26 in an assembly which is otherwise the same as that shown in FIGURE 1 and described above and they can also be used in somewhat similar assemblies where the sleeper is of metal.

Referring to FIGURE 5, the device is elongate and of substantially L-shaped cross-section, one leg 1 being for interposition between the top of a flange on a flangefooted railway rail and a first part of a rail-fastening member while the other leg 2 is for interposition between the edge of the rail flange and an anchoring member which is beside the rail flange and in which a second part of the anchoring member is inserted. The leg 2 has two projections 3 extending from it so that when the device is in use these projections can lie close to and on opposite sides of the anchoring member and can resist any tendency for the device to move in a direction parallel to the length of the rail by one or the other of the projections, according to the direction in which the movement tends to take place, abutting the anchoring member.

The device shown in FIGURE 5 consists of a metal member, shown in FIGURES 2 and 3, and a moulded member of electrically insulating material, shown in FIGURE 4. For example, the metal member may be cast from malleable iron and the insulating member may be of nylon. Both members are elongate, around 4 inches long, and of substantially L-shaped cross-section, the insulating member being longer than the metal member and projecting about inch beyond the metal member at each end. The Width of the device, measured horizontally in FIGURE 5, is about 1% inches and the height, measured vertically in FIGURE 5, is about /3 inch. Of course, the dimensions may vary substantially but it is considered that the useful range of dimensions is length: 2 to 8 inches, width 1 to 3 inches and height /2 to 2 inches.

The metal member has limb 4, in the leg 1 of the device, and a limb S, in the leg 2 of the device. A bead 6 extends along the tip of the limb 4 and a bead 7 extends along the junction between the limbs 4 and 5, both of these beads projecting upwardly when the device is in use. The projections 3 are part of the metal member and they project from opposite ends of it. At the sides nearest one another, they have parts forming shoulders 8 which are perpendicular to the adjacent surface of the limb 5.

The insulating member is about A inch thick and it extends around the tip of the limb 4, i.e., around the bead 6, across the lower face of the limb 4, i.e., the face which is on the inside of the angle of the L, and across the right-hand (considering FIGURE 5) face of the limb 5, i.e., the face which is on the inside of the angle of the L. Then a shorter portion 9 of the insulating member extends around the tip of the limb 5 and across the left-hand (considering FIGURE 5) face of the limb 5, i.e., the face which is on the outside of the angle of the L, between projections 3. The end surfaces marked 10 in FIGURE 4 face the shoulders 8 and are close to them.

The insulating member is on close contact with the faces of the limbs 4 and 5 which are on the inside of the angle. It is a snap fit on the metal member so that the two can be fitted together and then transported as a unit.

We claim:

1. A device for electrically insulating a flange-footed railway rail from a resilient rail-fastening member, a first part of which bears downwardly upon the top of the rail flange, and from an anchoring member, which is beside the flange and in which a second part of the rail-fastening member is inserted, said device being elongate and of substantially L-shaped cross-section, each leg of the L comprising electrically insulating material, one leg of the L being for interposition between the top of the rail flange and said first part and the other leg of the L being for interposition between the edge of the rail flange and said anchoring member, said other leg having two projections extending from it so that when said device is in use these projections can lie close to and on opposite sides of the anchoring member and can by abutting the anchoring member resist any tendency for said device to move in a direction parallel to the length of the rail, characterised in that said device consists of an elongate metal member (FIGURES 2 and 3) of substantially L-shaped cross-section and an elongate member (FIG- URE 4) of electrically insulating material which is a snap fit on the metal member and extends around the tip (6) of one limb (4) of the metal member, which is in said one leg (1) of said device, across that face of said one limb which is on the inside of the angle of the L, across that face of the other limb (5) of the metal member which is on the inside of the angle of the L and then around the tip of that limb, the arrangement being such that in use of the device the said first part (29) of the rail-fastening member directly engages said metal member and the rail (25) is electrically insulated by the insulating member from the rail-fastening member and from said anchoring member (22).

2. A device according to claim 1, characterised in that the projections (3) are formed on said metal member at opposite ends thereof and said insulating member extends between the projections across that face of said other limb (5) which is on the outside of the angle of the L.

3. A device according to claim 1, characterised in that along the tip of said one limb (4) there is a head (6) which projects upwardly when the device is in use, and wherein said insulating member extends around it.

4. A device according to claim 1, characterised in that along the junction between said limbs (4, 5) there is a head (7) which projects upwardly when the device is in use.

5. A device according to claim 1, characterised in that said insulating member projects at both ends beyond said metal member.

6. A railway rail-and-fastening combination comprising an electrically conductive railway sleeper, a flangefooted rail resting crosswise on the sleeper, electrically insulating material between the sleeper and the foot of the rail, an anchoring member which is beside the rail flange and is fixed to the sleeper, a rail-fastening member having a first part directly above the rail flange and also having a second part inserted in said anchoring member, and a device for providing electrical insulation which is elongate and of substantially L-shaped cross-section, each leg of the L comprising electrically insulating material, one leg of the L being interposed between the top of the rail flange and said first part and the other leg of the L being interposed between the edge of the rail flange and said anchoring member, said other leg having two projections extending from it close to and on opposite sides of the anchoring member which can by abutting the anchoring member resist any tendency for said device to move in a direction parallel to the length of the 15 rail, characterised in that said device for providing electrical insulation is a device according to claim 1.

References Cited UNITED STATES PATENTS 3,297,253 1/1967 Astley et al. 238349 3,369,753 2/1968 Olson 238283 3,387,781 6/1968 Moses et al. 238-283 10 ARTHUR L. LA POINT, Primary Examiner R. A. BERTSCH, Assistant Examiner US. Cl. X.R. 238-283, 349 

